Stiff steering
 

Daughter was driving her 2006 FX4 and called and said that the steering was getting harder to turn. I did not think it was the rack or pump. Called my dealer and he said it is always the U-joints on the steering shaft that corrode and get stiff. Truck was too far away for me to work on it. Had her spray the joints with WD-40, turn the wheel 180 degrees and do it again. After soaking a few minutes, she calls back and said it works fine now after the spray down. That was easy enough and cheap. Dealer said it is usually the joint by the rack that is the problem on these trucks.

My dealer said they stock the lower one but they have never had to replace the upper U-joint on any truck. WD-40 was just a quick fix until I can get the truck back home from 400 miles away to do it right. I was glad it was not a pump or rack issue causing this.

I have always packed those joints with grease, and have had no issues here, where there is more salt on the roads than there is asphalt.

i had the same issue. just replace the whole shaft. they are 75 bucks on amazon.takes about 15 minutes to change.

Happened to me a while back. Had to replace the lower steering shaft and that fixed the issue.

Just by sticking a grease gun in the joint, and filling it. Seems to keep moisture out.